1. Field of the Invention
The present invention relates to a fastening component and an appliance having a fastening structure and, more particularly, to an improvement of a fastening component including a shaft, a head disposed at an end of the shaft and a washer arranged at the end of the shaft. In particular, the present invention relates to a fastening component, in which an appliance having a fastening structure can be readily disassembled by using a washer made of a shape-memory member contractible in a radial direction with the application of heat.
2. Description of the Related Art
In recent years, air conditioners, washing machines, refrigerators, television sets and other electric appliances have aggressively taken the technique in improving the recyclability of appliances from the viewpoint of effective use of resources and consideration to the environment. In other words, the appliance is disassembled, and then, various structural bodies constituting the appliance are recycled. Specifically, there has been proposed a technique relating to an appliance having a fastening structure for fastening various structural bodies to each other by the use of fastening components such as a screw, a bolt and a rivet, the appliance being readily disassembled (for example, JP-U 02-36616 (1990) and JP-A 07-4407 (1995)).
JP-U 02-36616 (1990) discloses a washer made of a shape-memory alloy which is contracted in a screw axial direction with the application of heat. With such a washer, a screw fitted to a structural body is loosened by heating the washer, thereby facilitating detachment of the screw. However, there has remained a problem of complete detachment of the screw from the structural body when the appliance is disassembled.
In contrast, JP-A 07-4407 (1995) discloses a screw made of a shape-memory member, in which a tip of a shaft having a thread is bisected. Such a screw disclosed in JP-A 07-4407 (1995) uses no washer, although the screw can be readily detached from the structural body when the appliance is disassembled.
Otherwise, JP-U 04-113320 (1992) discloses a washer, in which a cutout is partly formed in an annular shape-memory alloy in such a manner that the cutout is enlarged in a lateral direction with the application of heat. With such a washer, the washer can be readily detached since the cutout is enlarged in the lateral direction with the application of the heat. However, an appliance cannot be readily disassembled.
Alternatively, JP-A 62-110013 (1987) discloses a spring washer made of a shape-memory alloy capable of suppressing degradation of a looseness stopping function due to thermal expansion. With such a spring washer, the degradation of the looseness stopping function of a screw can be suppressed, but an appliance cannot be readily disassembled.
As described above, there has remained yet the problem of the complete detachment of the fastening component from the structural body in disassembling the appliance in the conventional fastening components.